1. Field of the Invention
This invention relates to electronic detection systems, particularly to those systems for adaptively detecting vibration patterns.
2. Description of the Background Art
Electronic detection systems are frequently used for detecting vibration patterns emitted by various sources. Typically, vibration patterns are manifested as certain audible events having identifiable characteristics. In a number of different application areas, it is useful to detect these vibration patterns in order to recognize the occurrence of particular physical events that source such vibration patterns. For instance, in the automotive engineering area, electronic knock detection systems are used to detect noise bursts, or "knocks," caused by abnormal engine combustion. By detecting these events, it is then possible to modify combustion conditions correctively and thereby reduce fuel waste and lengthen engine life.
Various knock detection systems are known, as follows: U.S. Pat. No. 4,364,260 to Chen et al. describes an engine with knock-sensing apparatus having multiple-frequency tuning. U.S. Pat. No. 4,444,042 to Bonitz et al. describes a method and apparatus for detecting engine knock. U.S. Pat. No. 4,466,406 to Hartung et al. describes a device regulating an internal combustion engine. U.S. Pat. No. 4,637,247 to Dreyer et al. describes a method and system for recognizing knock signals in an internal combustion engine. U.S. Pat. No. 4,943,776 Polito et al. describes a device and method for detecting "pinking" in controlled-ignition engines. U.S. Pat. No. 4,969,440 to Murakami et al. describes a knock-suppression apparatus for an internal combustion engine.
Known detection systems are limited, however, in their ability to detect event vibration patterns which occur under dynamic and noisy conditions.